There are times which I found out some small details that makes me feel "Why does he/she have to do this? What is he/she trying to prove?"

Exactly the problem if its between ladies, 2 words, 心病. I personally feel there's less chances of that to happen between a female and a male.

Can't friends be just simple and fun-loving?
Unfortunately, backstabbers, hypocrites and liars exist!

Even if you think that you yourself are near perfect being sincere to frens and stuffs, pple can think otherwise.

Do you truely have, not 1 not 2 but 3, Best Friends? Do you find pple straying away from you or to gather only when you are useful?

Pathetic isn't it.
Just some thoughts. :)